System of electric-motor control.



P.0ONRAD.

SYSTEM OF ELEQTRIG MOTOR CONTROL APPLIGATIOH FILED snPT.1e,1g1u

1,024,557. Patented Apr. 30, 1912 R E a INVENTOR 2 ATTORNEY UNITED STATES P i ENT OFFICE.

FRANK com, 02 SWISVALB, Pkmwsnvnm ASIGNOB TO WES'I'HGHOUSB Eli-1w- TBJO AND muriwrumo COIPAHY, A. CORPORATION 01 PENNSYLVANIA.

sYsTmr or ELEGlBIC-IOTOB con'mon.

m n lwm n Patented Apr.30,191 AjplieatiuflcdSepheuberlB, mo. Seriallo. sags-ls To all whom it may concern:

Be it'lmown that I, Faun: citizen of the United States, and of Sw i$vale, in county of eny and State of Pennsylvania, have Invented a new and useful; Improvement in Como, a

Sfitems of Electric-Motor Control, of which following is a specifiea tion.

My invenhon relatesto systems of control for eleetric railway motors and portionlarl to over-speed devices for systems of the {more indicated class. k

object of my invention is to provide a system of oontml for electric locomotives which shall be afiupted to-autolnatieally limitthe speed thereof to: nedetermined maximum rate, irrespective o all other conconditions, due to T upon speedalone:

ditiols. I

In the use of electric lowinotiv structural necesarilyl'limit the maximum safe running and it is a matter of utmost impm'taneejto'mti-ict the operations safe limitations; Inasmuch .'as' are likely to he employer] in vafigmselase; of service and subpeted to a of loading Mews In aand ireightsof evidentthat sat: isiaetory' org-spear are adapted for such service. nn st'he dependent Itls well know-11in the w of an electric motor direetly propon tional. to voltage aypliedto jts'armr int-m! "to the field eurrent; in other'trnnls, tlispeedfof'a tor (lepemk upon the relative values 'of the armature voltage andthefield"em-rent: Thus,the me,

speed" nriess the ratio of voltage to current; or S varies e resident iion nfclti zirie unions;- e

time;

the

. at the switches has been inside, vice which depends for its action npon'the' relationship of eti'eoti vely serve Furthermore,

in :1 suitable over-speed dearmature voltage to field current and which is so constructed and i eonnected to the usual mntrolsystem, as to t Pu e tspecifiei 1 I provide means which' neoss'tates that the master controller be brou t i action of the over-speed before position, subsequent toe i voltage can again be applied to'tbemotorsfi' My invention is illustrated in the neeom'j- I panyin (lrawing, which is a view 0 the circuit connections of control for electric motors which an hodits my invention.

1t should-be'understoml of the system illustrated, to control the opemtion shown onlyas illustrative of-sneh a systemh h s flirted i of the lhotors. is

as miy be eqnipped with the SPeedJimiting device of my invention.

notemrfinui to but may be employetl with any t of trm which. is atlapted to gny'em My invention is anyspecifiesystem;

Referring to the ite'eompany ng thawing; the systenr tfolllprisrs a main 'snluli'vl -I- auto trnnsfonner winding 1 which is so plieil with energv from arsuitalile ei rmnt,

such-as: trolley conductor .4 andit track] speed railjl zn plurality of electric mot-us of the nom'nmtatur type, having ahnnlun-s l, 5

and 6 n-qmat-iwly, mumxansuting windings "i', S and 9, luiqn' ctively, an' lmain field" magnet windings 10, ll andrli' mpeetively, a set of switches '13 to 24, inclusive-, for govt-" ing the din-Minn of rotation f said motors; a Stitllltl set ofswilelll's 255 to 3G, inelusive,- for adjusting the eircuit ammo-- V f the motors ll-lithe illtQ-llllli ft'mner windingl; sebjof choke coils 3T, 383ml BQ an-angul as setforth inPatent No: 834,525, granted October 30; 1906, to

4 estingmuse Electric & Manufacturing (31., of Ray lQ-labltium, for the purpose of reventIng' injurious 25 to 36, inclr lsivc as the motor -(fo meetions,wit-h the auto-transformer are efl'ect d; a plurality of operatingor eontrolling magnets 4-0 to cal- 2 the operation of said switches; a reversing .switeh 41. to control the opernt ion of switches 13 to 24 inclusive, said reversing nals 42, 43 and 44 and movable contact segments 45 and 46 to cooperate therewithya master controller 47 for governing the operation of the motors, said master controller comprising a .plm'alit of stationary contact terminals 48, and a movable contact segment 49 to cooperate with saidstiitionary terminals upon the position-indicat' lines a to l, Inclusive: an auxiliary 1. inter 'ng mums for a purpose hereinafter explained, said means comprising a movable conducting segment 49", mdependently asoeiated with master controller 47, and stationary contact terminals 48; a bat- It!!! or other'suitable source of energy 50 from which the operating magnets 40 re eeive their excitation: an over-speed limitin: device 51, adapted tointerrupt the apphcntjon of ene to the motors under pre- 3 determined conditions and comprising relay mi 52, and 53, respectively, de

penden t upon the armature voltaQ and field current of one of the inotorsfand a pirotally supported member adapted to wlmectthemorablewrrsof said relay coils;

and an auxiliary relay coil 55 which isdet u the action of said orer-speul dergh il and the auxiliary interwithsaidmaster a comm for the purpose of preventing further of energyto the motors untilthe maflercontnfllerfihasheenreturned to its 'Foipos'itiu m.

It will he evident to skilled iii the. art that, helow. msjnuun allow- I of the orer-s ml device '1 f fiinreulim is dam 4 t t o t system, in it way with-the 1 tion of tint of the system ofthemotors'; m -gi gzfi'mfi the motorrermng" "portiono system my 1-: s5;- ie tl who m r slid-ore In the: fllesystem, revels ing switch 41 it heaused to opentte m either direction forgoremin the direction:

of rotation of, he motors ff forinnlrolaliuizfis di is rinsed contact termina'B 2 and] fj control magnets 13, 16; 17, 20, 31' and il-{to be apd said switches to he closed; T "For rontart :a-gn'n-n't; l6 Braised to statim'iary ow aft 43 and -14, iii Whit-ll [itsilinn the arr-thr lling s 40.1If5fllll'lltfi ll.

I contact tor speed condi for my predetermined criticalspeed, a dc over-51ml device 51 is adjusted 1'5, 18', 1s, 22 sis-again; a d um The drum i nun ed into it causes switch 25 to be closed in the positions 6, cand d, it causes the closure of switches 26, 27 and 28, rspectively. As the master controller is moved through the sucpositions e to l. switches 29 to 36, inclnsive,' are closed in succession, and Switches to 32, inclusive, are succesively opened. Since this portion of the system is fully described in the above mentioned Patent No. no further detailed description of the system is considered necessary.

Reference may now behndto the overspeed device 51. The relay coil 52 or the socalled voltage-ooil is connected am the armature 6 and 9 and hence its energization is dependent upon the voltage applied to-siid armature and compensating windi For the purpose of adjustment, a raria non-inductive resistance 6 is connected in circuit with said relay coil. Relayfcoil 53 is the so-called current coil and is to a secondary winding 57 of a seriestramaformer, the primary winding 53 of which is in Mics circuit with the field magnet winding lQ, armature 6 andcolnpensating windin 9. Hence, the action of said coil ent upon the field current which, in this case, also traverses the armature. 'Onc end of connecting member provided with a dash pot 53', of construction, to dampen out any undue vibrations, and the other enrlof-said conneeting nleiubcr is provided with a switch member 59 which engages a set of stationingcontact terminals or under predetermined Auxiliary 55 is r'rith'n switch member 6 1, which, under normal stationary contact terminals 62,-hut "makes contact with upper contac t'temiinals 63 when said relay In to adjrst the over speed device 11. termination of relative ralua of armature roltage field current to produce the ',isnecmry. Ha ascertained the ratio hdween farmature vol and field current to rodnce the particular speed for which the 1 rice is to he art, the

meansof weighls not shown) and the variable resistalm- 56, an that cited: of the 7' T (I'll 5 shall ll: ill ("Sm 0f the current coil ',53, when said Cri'fiml spa-d attained. "once, it i evidengsinee a particular s x-cd is dependent upon the ratio between the anoalure voltage and liol-l rnrn'lll', and not dependent upon' per licular \zllluri of said roltage and current, that, whenever the locomotive attains the critical speed for which the oversxed derice is adjusted, the efl'ect. of the voltage coil 52 will overlnlance that of the our rent ('Uil 5 thereby eausin switch mein her to make vontart with stationary rontacit terminals tJ l.

Assuming the various pieres of apparatus and eirrnit eonnections to he as shown in the diagram the operation of the over-speed dtu ice in aetual servioe is as follows: As the locomotive is started from rest, a heavy rurrent is applied to the motors at a, low voltage. hem-r the pull exerted hy the current (soil 52, is in excess of that of the voltage i it" .\s the speed of the loeonmtire gradually inrreases, the voltage applied to the motors likewise inrr asetii and the motnr torrent gradually decreases until Stlt'l] conditions are produced that. the ett'ec't upon tho Voltage (oil 62 of tho voltage applied lo the motors predominates over the pull t'\l'ittftl hy the "ruri'ent coil" 53, indi ating that the rritiral speed is attained. Switrh nenilier' Lil then (-loses upon eonlai't terini nil itl thereliy estahlishing a ('irruii from tin positiie side of hattery fit), through eon din-tor fit, one of rontaet terminals 43'', eon dot-ting segment it)" other tontaet tern'iinal is. (:ondiu'tor (3.7, switrh inemher 59, (ondurtor ti l. auxiliary eoil 55, eondur-tor 7 and rondurtor 38 to the negative side of the halter-y. The rompletion of this eireuit iau r relay roll 55 to he energized and suiu-h meniher til to he disengaged from ontart trrluinals G2 and to make eontai-t with tntai-t terminals (33. As the switnh nu-niher t l disen 'agts its Contact terminals 6:, the main rontrol oireuit, from the positi\e side of the hattery 50 to the master routroller, is interrupted and all of the eontrol nuignets it) are thereby dei nergized, rausing ail of the switches to he opened and the ap plieation of voltage to the motors to he diseontinueitl.

it will he ohserved that as switrh meinlier il mains mutant with upper rontat't tea-mi nals 63%, a shunt rrirruit around the switeh ineinlier St) is estahlished through ('ondiu-tor so. switrh mend-er hi and conductor 70. Thus. the auxiliary relay fifeontinues to he energized, irrespwtive ol th subsequent op eration ol' the ownspeed device 51, until the master rontroller i7 is moved into its ott' position and the energizing eirenit interrnpti-d.

The various r-iri'uits ot the system and the slruirtln'al details of the tl'vires t'or arranging the lrli'iilit i'onina'tions may oliriously he ni dilii-d ronsidi-ralil within limits, without departing from the spirit and s ope of my inu-ntion, and I desire that only siu'll limitations shall he imposed as are unlimited in tin: appended elaims.

i rlaim as my invention:

l" in a system of (-ontrol, the romhination uith a souri-e 01' energy, an electric motor having a field magnet winding and an armatur winding, means for vontrolling the-"enorgy applied to said motor and means dependent on armature \oltagr and lieid rur rent [or limiting th speed of said motor to a predetermin il 'va or. of nzeans dependent upon the operation ol' said last named means tor atl'ei'ting the operation ot said rontrolling means.

2. In a system ot eontrnl, the i-omliination with a sourre l' en rgy a plurality oti elm: trie motors nit-ans i'or i-onirolling the energy :lllllllit' l thereto and means dependent upon n'iwh=t ruiirn-d spot-d ronditious 'i'or eausing a change in the supply of energy. of means for rendering further ehanges in the supply (it energy dependent upon predetermined conditions.

it, in a system of vontrol. the tUHllJilliltlOll with a sonife ol energy. an eh-etrie motor having a tield magnet winding and an armature inding. means for eontrolling the energy applied to said motor, and eleetioresponsive inc-ans dependent upon the ratio ot armature 'oltageto tiehl current for etl'eetii'ig a change in the su 'iply ot energy, of means dependent upon said elm-trode sponsii'e m ans for rausing further r-hanges in t'ie supply ol energy to he dependent upon predetermined conditions.

4. in a system ot eoutrol the (roinhination with a sonri-e ol' energy. an elertrit: motor, rirenit-rmitrolling means for governing the energy supplied to said motor, and elm-t 1o responsive m ans dependent upon pr deten mined speed ronditions t'or interrupting the supply of energy. of means dep ndent on said elem-tiirresponsive'means for rend ring further supply of energy dP 'iendent upon a predetermined operation ol' said nireuit-controlling means.

ft. The vomhination with an eleetrie n'iotor and means for ontrolling the operation thereof, of a pin 'aiity of relay (-oils respectively responsive to armature \oltage and field rurrent and adapted to act in opposi tion at the opposito ends of a pirotally mounted arm, and a third relay roil dependent upon the resultant operation of the aforesaid relay c-oil t'or interrupting the supply ol'- energy to said motor.

1. The ronihination with an electric motor, means for irontrolling the operation thereof and an overspred limit dovit'e comprising two relay rolls arranged in oppositi n and respri-tiw-iy responsive to armature voltage and field rurrent and a third relay coil dependent tor rm-rgizalion upon the re sultanl operation ot said opp sing (oils for interrupting the supply ('lltliit of said mo tor. ol' means assoi-iated with said third to ia t'illl lor rrinlering its det nergization independent ot the suhsezpu-nt action ol said over-spend limit device.

7. \n over'speed limit deviee for electric motors eoniprising two opposed relay coils, resl'ioctirely responsive to ditt'i-rent electrical circuit conditions, :1 third relay coil adapted to etlcct the interruption of energy to said motors in accordance with a predetermined resultant operation of said opposed relay coils, and means for rendering the further operation of said third relay coil independent of the action of said opposed relay coils.

In a system of control, the combination with a source of energy, a plurality of electric motors having armature windings and licltl magnet windings, and a circuit-controlling device for governing the energy applied to Slilll motors, of means responsive to armature voltage and field current. for interrupting the energy applied to said motors under prctletcrminetl speed conditions and separate means for preventing further application of energy to said motors until said cireuit-controlling device is moved to its off position.

5 The combination with a plurality of electric motors having armature windings and field magnet windings, and a unit switch control system adapted to govern the operation of said motors of relay coils respectively dependent for energization upon armature voltage and field current, a pivotallysopported connecting member, the op llosilt' ends of which are pivotally secured to the movable core members of said relay coil: and means for interrupting the auxiliary control circuit under predetermined unbalanced conditions of said relay coils.

ill. The combination with a source of energy; a plurality of electric motors a pin lt\lll of unit switches adapted to establish circuit connections for said motors, an auxiliary control system adapted to operate said unit switches and a controlling device for arranging circuit connections of said auxil iary control system, of two relay coils ar ranged in opposition, said coils being respectively responsive to armature voltage and field current, a switch member associated with said relay coils and dependent for its operation upon the resultant action of said coils, means associated with said switch member for interrupting said auxiliary control circuits under predetermined speed conditions and means for maintaining the intcrrnption of said circuits until said controlling device is moved to its off position.

11- An over-speed limit relay for electric motors comprising two relay coils arranged in opposition, said coils being respectively responsive to armature voltage and field current, a third relay coil associated with said opposing coils and dependent for energization upon the resu tant action of said opposing coils and a switch member associated with said third relay coil and adapted to cause the interruption of energy applied to said motors under predetermined speed con-- ditions. In testimony whereof, I have hereunto subscribed my name this 12th day of Sept, 1910.

FRANK CONRAD. \Vitnesses Wham M Bltmsimw, 15. B. l'iINES. 

